feat(structured-output): add typed helpers for structured JSON (RunJSON, RunStreamedJSON)

[activadee]

Summary

• Add typed helpers to generate and decode structured JSON directly into Go types.
• Support both single-shot (RunJSON) and streaming (RunStreamedJSON) flows.

Details

• Infer JSON Schema from the generic type parameter using invopop/jsonschema (overridable via options).
• Emit SchemaViolationError when the turn fails schema validation to allow precise handling.
• Provide a streaming result that yields typed snapshots alongside raw events.

Docs & Examples

• README: document typed helpers with a short sample.
• Example: examples/structured_output demonstrates RunJSON and RunStreamedJSON usage.

Tests

• Cover happy-path decoding, streaming lifecycle, and schema violation classification.

Chore

• Update go.mod/go.sum to include github.com/invopop/jsonschema and related indirect deps.

Notes

• Intended to make structured output ergonomics safer and simpler for Go users.
• Addresses SDK DX: structured output helpers (RunJSON[T], RunStreamedJSON[T]) #11 .

[github-actions]

Codex Review Summary

Recommendation: ✅ Ready to merge – no blocking issues detected.

Summary:
No blocking issues found. Removing the <-raw.stream.done escape path ensures the fan‑out goroutine always reaches the post-loop turnCompleted check, so callers now observe ErrNoStructuredOutput instead of a spurious nil. The update still drops raw events when the consumer is absent thanks to the default branch, so there’s no risk of regressing into the earlier deadlock scenario.

Inline findings:

• No inline findings.

Generated at 2025-11-06T19:05:52.662Z.